Toro Rosso failed to get either car home in Canada - Credit: Peter Fox/Getty Images

Franz Tost admitted the Canadian Grand Prix weekend was one to forget for the Scuderia Toro Rosso team, with neither Daniil Kvyat nor Carlos Sainz Jr seeing the chequered flag.

The Team Principal of the Faenza-based squad felt Kvyat was unfortunate that a stall on the grid had a drastic effect on his afternoon, with the Russian failing to regain his grid position in time in order to start from his eleventh placed grid slot, although he did start there and earned himself a penalty.

Kvyat then suffered more disappointment when a wheel nut problem cost him a lot of time in the pits, with his race ending not long after when out of contention for points.

“Our Canadian GP race weekend has been a difficult one – it all already started in yesterday’s qualifying session, where we didn’t manage to get the cars into Q3,” said Tost. “We started the race from P11 with Daniil and P13 with Carlos.

“Unfortunately, Daniil’s engine stalled at the start of the formation lap – we need to investigate how this happened, because there’s no excuse; an engine should never stall and there must be a technical solution to avoid this from happening.

“The regulation allows the driver to catch-up until the first Safety Car line but as all the drivers use the complete width of the track to warm-up their tyres, it was difficult for Daniil to overtake them in order to get back to his position without taking any risks.

“Therefore, he just missed overtaking Alonso before the Safety Car line – it was also too late for him to go into the pit-lane – so he got penalized for this. Daniil did a very good race and was very competitive, putting in some really good lap times.

“We then had to call him in for his pit-stop and for him to serve a ten-second penalty that was in addition to the drive through he had already been given, but we suffered a problem with the rear-right wheel-nut. Therefore, we decided to retire the car because, at this stage, we were two laps behind.”

The team also saw Sainz crash out of the race on the opening lap after a clash with Romain Grosjean, with Tost disappointed that they were unable to consolidate their fifth place in the championship with another points finish.

“Regarding Carlos, he had a reasonable start but then collided with Grosjean at Turn 3 and this was the end of his race,” said Tost. “Unfortunately we leave Canada without scoring any points and with a bag full of work to do for next race in Baku.”